In Rudra case she saw him shooting her husband right infront of her eyes, she grown up in a village where everyone believes "BSD" Officers are the bad guys... She has every right to not believe any words that comes out of his mouth because for her he's just using her & keeping her alive only as his witness.
For Paro to come to know Thakur true colors, Rudra will take the bullet for her and that's when she will realized Rudra has been telling the truth all along.
Paro is totally justified today for not going against her father figure.